Effects of propranolol compared with clonidine on portal haemodynamics: a double-blind cross-over study using duplex-Doppler ultrasonography.

Background: Patients with liver cirrhosis and large oesophageal varices run a high risk of digestive haemorrhage due to the rupture of oesophageal varices, an event associated with a high mortality. At present, the only treatment for the prevention of first bleeding from oesophageal varices on which there is general agreement is drug-based. In order to tailor drug treatment to the requirements of individual patients more precisely, an ever-increasing number of drugs is being investigated.
Design: Double-blind cross-over study.
Methods: Sixteen cirrhotic patients with large oesophageal varices were studied by means of duplex-Doppler ultrasonography to determine variations in portal haemodynamics after oral administration of 0.150 mg clonidine and to compare these with the variations observed after oral administration of 40 mg propranolol.
Results: Propranolol caused a significant reduction in maximum portal flow velocity (P < 0.001), whereas clonidine failed to cause any such variation (P = 0.194). Considering as responders those patients who exhibited at least a 10% decrease in maximum portal flow velocity, 11 patients responded to propranolol; of these, three also responded to clonidine. No patient responded only to clonidine.
Conclusion: The absence of any effects on the parameters of portal haemodynamics would appear to deny clonidine any significant role in preventing first bleeding resulting from the rupture of oesophageal varices.